The invention set forth in this specification pertains to new and improved sprinkler structures. More specifically it pertains to sprinkler structures which include water distribution, discharge or spray structures and which are constructed so that such distribution structures can be easily removed and replaced for cleaning purposes or exchanging one such distribution structure for another.
The sprinkler structures of this invention are intended primarily to be used for agricultural and horticultural purposes. Normally they are employed to distribute a comparatively small volume of water from a supply of distribution tube or manifold to the area immediately surrounding them. Not infrequently it is desirable or necessary to change the nature of the spray of water produced by or obtained from the use of such a sprinkler structure so that the spray will cover a different area than before or so that the spray will be of a different character than before. Also it is rather common to have to clean out accumulations of various sorts within such spray structures so that they will operate satisfactorily.
As a result of these considerations a number of different types of sprinkler structures have been developed which use easily replaceable discharge or spray structures to create various different sprays or spray patterns. Unfortunately it is not considered that one of these prior structures is completely desirable or acceptable for common agricultural or horticulturist purposes for one or more of a series of reactions. This is best illustrated by referring to various different types of known sprinkler structures having easily replaceable distribution or spray structures.
For discussion purposes it can be considered that those of such prior sprinkler structures which are of the most significance in connection with this invention fall within three different groups or classifications: (1) those using a wire bail to hold a distribution port or spray structure so that it can be easily detached from or replaced on a sprinkler structure; (2) those using a post extending above and/or over a discharge opening or nozzle to hold a distribution or spray structure opposite the opening of the nozzle; and (3) those using a post extending along side of a stream from such an opening or discharge nozzle to hold a distribution structure so that it can be adjusted along the length of the post to various positions in alignment with the discharge opening or nozzle.
It will be recognized that this listing of three different types or manners of constructing sprinkler structures having replaceable distribution, discharge or spray structures does not designate all of the multitude of various different types of sprinklers or sprinkler structures which have been developed so as to include removable or replaceable distribution or spray structures. This can be illustrated by referring to sprinkler structures having sprinkler heads which can be screwed into and out of a socket for replacement purposes. These are not considered to be particularly significant with respect to the present invention because in general they are not as easy to manipulate in removing and replacing distribution or spray structures as those constructed as indicated in the preceding discussion. Also as a class such structures using threads are considered to tend to be more expensive than sprinkler structures as indicated in the preceding discussion.
Those sprinkler structures which use a wire bail are unquestionably utilitarian in character in that they are constructed in such a manner as to permit rapid, easy removal and replacement of the distribution part of a structure such as a spray or deflector head. In spite of this it is considered that in general they are not desirable for many agricultural and horticultural uses in which small or limited volumes of water are discharged because of the cost of such structures. This is related to the fact that the bail in such a structure has to be of a comparatively large diameter wire if it is to be strong enough to adequately operate in holding a distribution structure such as a spray head in place in such a structure.
The use of a comparatively large bail is undesirable because of cost and weight considerations. On the other hand if a comparatively small wire bail is used it will not have the desired strength characteristics. Also any comparatively inexpensive wire bail is subject to corrosion. Further, known sprinkler structures of this bail type are constructed in such a manner that only limited types of spray heads or other water distribution or spray structures can be used with them.
With sprinkler structures of the other types indicated in the preceding which are constructed for use in spraying comparatively small volumes of water, corrosion problems such as are inherent with normal steel wire bails are avoided by forming all or substantially all of the parts of such structures of common, relatively inert thermoplastic polymers. In general sprinkler structures of these other two types are relatively inexpensive because of this. However, known sprinkler structures of these other types are designed in such a way that functional problems tend to be encountered with them.
For example, those sprinkler structures of the second of the classes indicated in the preceding are limited in that they cannot be effectively used with discharge structures or heads of such a type that all of the water passing through a sprinkler structure has to pass through a nozzle, a slit, a series of either of these or the like in the discharge structure or head but instead are designed so as to be employed only with discharge structures using one or more deflecting surfaces designed to receive and deflect a stream of water from a nozzle or nozzle-like discharge opening. While in some applications it may not be necessary or desirable to use other than a deflecting type distribution structure in others it is considered the need to use such another type of structure is significant.
It is also considered significant that in any sprinkler structure of the second and third types indicated in the preceding discussion there is normally a need for the precise placement of the deflecting surface relative to the nozzle or nozzle-like discharge opening. There are two aspects of such placement: (1) the alignment of the deflecting surface with a nozzle or opening; and (2) the correct spacing between the deflecting surface and the nozzle or opening. If both of these factors are not considered there is a reasonable possibility that a desired spray will not be obtained. Many of the various sprinkler structures of the last two of the types noted are considered to be normally constructed in such a manner that it may be difficult to consistently achieve the desired placement of the deflecting surfaces in the distribution structures employed in such units, particularly under field conditions.
In the latter circumstances individuals are not apt to spend the time to make sure that any distribution structure is precisely installed in a desired manner in a sprinkler or sprinkler structure. Such installation is believed to normally be important in connection with plastic sprinklers in which the distribution or discharge member containing a deflecting surface is frictionally held in place after the insertion of a small shaft in a correspondingly sized hole. With the latter and related structures in which only friction is used or is used in conjunction with a small detent to hold or deflector or the like in place it is considered that there is always a degree of danger of the deflecting surface in such a structure either not being properly positioned or of getting out of position as a result of ambient conditions.